A ship is heading due east at 20 knots. Three nautical miles due north of the ship is a rock. The ship must make a course change when the rock is 5 miles away. How many minutes will it be until the course change?
Then it has a picture of a right triangle with sides 3 and 4 and hypotenuse 5. There is a picture of a rock at the angle where the 3 and the 5 meet. Any help would be greatly appreciated, thanks!